Caprice32 184.108.40.206 is the latest addition to the collection of emulators. It's an Amstrad CPC emulator, and is my second choice for a port. My initial attempt was to port Arnold, which is a (arguably) more accurate emulator, but due to its poor performance on the PSP (~15 fps), the idea was scrapped.
Caprice32 is a lot faster, though the rendering subsystem used in the current version is from version 4.1.0, for performance reasons. If/when the renderer is optimized, the PSP port will be updated to reflect the change.
Current version is also missing ZIP file support - this will be implemented if enough people express interest.